A 6.4 mW, 4.9 nV/√Hz, 24 dBm IIP3 VGA for a multi-standard (WLAN, UMTS, and Bluetooth) receiver

摘要

A low-power high-linearity variable-gain-amplifier (VGA) to be embedded in a multi-standard receiver (WLAN, UMTS and Bluetooth) is reported. The multi-standard receiver architecture presents considerable different VGA requirements (in terms of bandwidth, DC-gain, noise level, and common mode input voltage) for the three telecom standards. The VGA is positioned just after the mixer, and, then, it operates on low- amplitude input signals. This results in stronger noise requirements than linearity ones. Thus a digitally controlled open-loop structure has been used. The prototype VGA is realized in a 0.13 μm CMOS technology and it features gain levels from -10 to 36 dB. For 0 dB DC-gain it exhibits a 25 dBm IIP3 and an input-referred noise voltage lower than 5 nV/√Hz. This gives a 85 dB-DR for the WLAN case. The VGA draws 6.4 mA from a single 2.5 V supply.